Vieira et al., Helvetica Chimica Acta, 65(6) (1982), pp. 1700-06, teach the preparation of the oxabicyclic cyanohydrin acetates ##STR1## via a Diels-Alder reaction. In addition, the publication discloses epoxidation of the above compounds with m-chloroperbenzoic acid to yield ##STR2## as well as the hydrolysis of such compounds to yield ##STR3##
Vieria et al., Helvetica Chimica Acta, 66(6) (1983), pp. 1865-71 teach a chiral variant of the above described reaction which produces oxabicyclic cyanohydrin esters homologous to those depicted above, but with a (-)-camphanoyl group instead of an acetate group.
Black et al., Helvetica Chimica Acta, 67 (1984), pp. 1612-15, disclose a method for the preparation of the chiral oxabicyclic ketone ##STR4## via diastereoselective formation of a brucine complex of the corresponding cyanohydrin acetate.
Payne et al., U.S. Pat. No. 4,567,283 and Payne et al., U.S. Pat. No. 4,670,041 disclose a variety of herbicidal bicyclic ethers of the Formula ##STR5## wherein X is (--CR.sub.4 R.sub.4 --).sub.m in which m is 0 or 1; Y is (--CR.sub.5 R.sub.6 --).sub.n in which n is 0, 1 or 2; Z is (--CR.sub.7 R.sub.7 --).sub.p in which p is 1, 2 or 3; the sum of m+n+p is an integer of 2 to 5, inclusive; R.sub.2 and R.sub.3 each is H or alkyl, and the like; R.sub.1 is H or alkyl; both of Q are H or F atoms; and W is an unsaturated, aromtic or heterocyclic group. This reference also disclosed certain bicyclic and monocyclic intermediates to these compounds.
Payne et al., U.S. Pat. No. 4,525,203, disclose herbicidal bicyclic ethers of the Formula ##STR6## wherein X is a single bond or --C(CH.sub.3).sub.2 ; Y is a single bond or --CH.sub.2 -- with the proviso that both X and Y are not a single bond, and Z is H or alkyl; each R is H, hydroxy, oxo, methylene, alkyl or alkoxy, or one pair of adjacent R groups form a carbon-carbon bond; and R.sup.1 is H or alkyl. This patent also discloses certain bicyclic and monocyclic intermediates to these compounds.
GB No. 2188-931 discloses compounds of the following formula as herbicides: ##STR7## wherein
W and X is O or CH.sub.2 ;
Y is C--C bond, O, CH.sub.2, CH.sub.2 CH.sub.3 or CHR;
Z is C--C bond, O, CH.sub.2, CH.sub.2 CH.sub.3. provided W, X, Y and Z are not adjacent O or C.sub.2 H.sub.4.
J. Chem Soc. Perkin Trans. I, 903-906 (1985), J. Amer. Chem. Soc., Vol. 84, 4115-4125 (1962) and Aust. J. Chem., Vol. 36, 2473-2482 (1983), disclose intermediates such as I, II and III, respectively, useful for the preparation of the compounds of the invention. ##STR8##